{smcl}
{* June 2011}{...}
{cmd:help singleb}
{hline}

{title:Title}

{p2colset 5 18 20 2}{...}
{p2col :{hi:singleb} {hline 2}} Contingent Valuation using Single-Bounded Dichotomous Choice {p_end}
{p2colreset}{...}


{title:Syntax}

{p 8 17 2}
{cmd:singleb} {varlist}  {ifin} {weight} [{cmd:,} {opt level(#)} {opt noconstant}]


{title:Description}

{pstd} 
This command uses maximum likelihood (under the assumption of normality) to estimate the single-bounded dichotomous choice model 
for contingent valuation (Cameron and James, 1987). This command provides an alternative to the estimation via {cmd:probit}. 
The main advantage of this procedure is that we directly obtain point estimates (and standard errors) of the marginal effect that  
a change in the explanatory variable has on WTP.{p_end}

{title:Remarks}

{pstd} 
The first variable in {varlist} should be the bid variable. The second variable should be the dummy for the response to the
dichotomous choice question. The remaining variables will be interpreted as covariates or control variables.{p_end}

{pstd} 
For the constant only model the constant represents the mean WTP. For the model with explanatory variables the mean WTP can be obtained by 
multiplying the mean vector of explanatory variables by the vector of estimated coefficients.{p_end}

{title:Examples}

{phang2}{cmd:. singleb bid response}

{phang2}{cmd:. singleb bid response x1 x2}

{pstd}Use file singleb.dta to do the examples {p_end}


{title:Author}

{p 4 8 2}Alejandro Lopez-Feldman{p_end}
{p 4 8 2}Centro de Investigacion y Docencia Economicas, CIDE{p_end}
{p 4 8 2}Email: {browse "mailto:lopezfeldman@gmail.com": lopezfeldman@gmail.com}


{title:References}

{phang}Cameron, T. and M. James. 1987. Estimation Methods for "Closed-Ended" 
Contingent Valuation Surveys. {it:Review of Economics and Statistics} 69: 269-276.



{title:Acknowledgments}

{pstd} 
I thank Brett Day for sharing the Stata code that helped me to get started writing this command.